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As demand grows, utilities say designs are safer; financing remains an issue (http://www.msnbc.msn.com/id/20841590/)

http://www.cleanmpg.com/photos/data/501/Nuclear_Plant.jpgAP - Sept. 19, 2007

NEW YORK - The current turmoil in credit markets is unlikely to derail plans by power companies to begin ordering the first new nuclear plants since cost overruns and public opposition virtually killed the industry three decades ago.

Nearly 30 years after the disastrous partial meltdown at Three Mile Island, Pa., several companies are planning to seek regulatory approval to build new plants, including Entergy Corp., Dominion Resources Inc., Exelon Corp. and the Tennessee Valley Authority.

Constellation Energy Group has already filed a partial application with the Nuclear Regulatory Commission, which expects up to seven requests this year and 28 by 2009. The first plants could be online by 2014 or 2015… http://www.msnbc.msn.com/id/20841590/

Wow, France's grid is 79% nuclear. Combined with the high average mpg of European autos, their emissions per capita must put us to shame (instead of just beat us significantly).

I may have to look some of this up.

And they do......

http://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita

Edit: Amazing when you just stop and ponder. French citizens, with a living standard roughly equal to our own, emit only 30% the CO2 per person that US citizens do.

But would we really want to trade CO2, which we may be able to deal with, for nuclear waste, which we can't destroy?

Also, where is the money coming from? Without government subsides these things don't seem affordable. I found an article indicating the worlds largest nuclear power plant was scheduled for Portugal, and its only 114MW. There are wind generation clusters near or larger than this size planned all over the U.S.

With the potential risks of nuclear power, and NIMBA potentially being hundreds of miles down wind from any plant...why risk it where there are other cheaper, safer options available. The UK started going this way, and realized that with their wind/wave resources, there was no point. I don't think we need to go that way either.

The thing about concern over nuclear waste is this -- we haven't been smart about putting the "waste" to work.

Nuclear plants work by (essentially) heating water to power enormous steam turbine generators. The way most are designed they need highly reactive "core" material -- these are just highly enriched radioactive rods. These rods are considered "spent" when their radioactivity drops below a certain threshold and then are discarded. This is the stupid part.

What we should be doing with this "waste" is putting it to work in smaller applications that do not require such high output. Imagine taking those "spent" rods and using them to power a few neighborhoods or a company campus instead of a city? Once output is too low for that, something less demanding like one neighborhood or a large building? Then down to a single house? A backup generator? A battery charger? A low power environmental sensor or small marker light?

The idea is to keep using it until the radioactivity really is pretty much "spent." Then disposing of the "waste" isn't nearly as bad because the level of radioactivity is so much less at that point.

We have to get over this phobia of "it can hurt us!!!" and get smart about how we can use our resources. Yes, it is dangerous. So is just about everything else we play with on a daily basis. And we deal with it -- as we should in this case as well. Newer plant designs don't even require the same level of fuel refinement to run -- which makes them both cheaper to build/run and cheaper to fuel (no need for the extremely expensive refinement processes to get the really reactive stuff).

Sorry, you touched a hot button for me. :o

I found an article indicating the worlds largest nuclear power plant was scheduled for Portugal, and its only 114MW. There are wind generation clusters near or larger than this size planned all over the U.S.


I recommend finding more reliable sources. 114MW is tiny. Typical reactors being built today are in the 1000MWe range, with some even larger. And don't get me wrong, I would be absolutely thrilled to see renewables take over. But right now they don't produce the kind of base load capacity that we need. So the US your choice is basically coal or nuke. The waste is definitely a problem, but the public perception of safety tends to look a bit hysterical relative to reality. Are there concerns? Absolutely! Is a radioactive cloud a realistic possibility? Not in the US. (You can thank the Soviets for failing to take even the most basic safety precautions in the design and operation of Chernobyl, not to mention that it was an idiotic design to begin with and they knew it. Three Mile Island failed but it did so according to design: without killing people.)

On the brighter side of things, I'm a big fan of the German solar power model. (Pardon the pun.) They've been subsidizing panels and people slap them up everywhere. Depending on who you ask, they may achieve a 30% share of electrical energy from photovoltaics by 2020. They're pretty much guaranteed to make 20%. They still need plenty of conventional capacity to make up the balance and for when the sun doesn't shine but at least they're doing something.

Sorry I used an old reference, but it was the best I could quickly find. I'm actually quite surprised to find nuclear appears to be cheaper than almost all power sources except cheap coal, even when including decomishining costs.

I was going to say more, but frankly its all a matter of opinion. I'd be willing to pay more for electricity and have it come from wind,wave,tidal, and solar instead of nuclear, coal, or oil. I'm unhappy to see additions of any of these kind of stations. I do realize we would need excess renewable sources or a way to store power, and both of these seem to be feasable now at excess cost or in the next 15/20 years at reasonable costs. And I'm absolutely horrified at the US being in involved with nuclear power & having nuclear weapons while having a president who can't actually pronounce the word correctly :)

As something a little more friendly towards nuclear power...one q&a about nuclear power has the question, "will cars ever run on nuclear power?", to which the expert said never; it wouldn't be safe. Well with the addition of plug ins, we might all be able to run on some nuclear power....and wind...and water

Yeah, you will never see a nuclear reactor in a vehicle other than a sub or aircraft carrier. I only know of one technology that **might** work, which involves bombarding hafnium with an x-ray to produce large amounts of gamma radiation. (Which is kind of an odd thing to say since x-ray radiation is gamma radiation, but whatever.) That gamma radiation provides your heat source to run a turbine, which has been proposed as a way to fuel aircraft. That's all well and good except that you need very heavy lead shielding to protect organism from gamma radiation. Not practical! So we can all breathe easy about that one.

Yeah, you will never see a nuclear reactor in a vehicle other than a sub or aircraft carrier.

http://upload.wikimedia.org/wikipedia/commons/4/41/TaskForce_One.jpg

Somebody mind telling these guys they need to go retrieve a couple of ships? CTF-1, 1964. AKA Great White Fleet II.

Personally, I'm OK with intelligent nuclear power. The Hanford/Chernobyl/Enterprise stuff pisses me off, but carefully used nuclear (especially sodium or other non-depleting reactors) is probably the best source of power for places like C. IL where wind/solar/small hydro can't fulfill all the needs.

And NO, our library is not a bunker (Go Illini!) :).

Actually new fuel isn't very radioactive, spent fuel is highly radioactive due to some the isotopes that are created in the fission process. One of the problems with utilizing the 'spent' fuel in something else would be the security involved to keep it from being used in a less desirable fashion. The shape/configuration of the fuel may also be a problem.

That gamma radiation provides your heat source to run a turbine, which has been proposed as a way to fuel aircraft.

I remember the nuclear plane...the X-6 program. It actually did carry a small working reactor, but they never powered the plane with it. Here is the wikipedia link.
http://en.wikipedia.org/wiki/X-6

Do you think as fuel prices go up, the largest cargo ships might start being equiped with reactors?

Bucko, I'm having a hard time making sense of your statement. You want the fuel to be as reactive as possible so that you can create as much steam as possible. Higher levels of radioactivity = higher levels of thermal output. Additionally, radioactivity always decreases. That is why we have something called "half life" associated with radioactive materials. That defines the time needed for the radioactivity to drop to half of its initial measurement.

While it is true that there are more isotopes giving off radiation in a "spent" rod, I have a hard time believing that the sum total is releasing more than the initial rod. If it was, wouldn't it be more efficient than the initial rod? In which case, why do we bother purifying the initial fuel? :confused:

Do you have any resources to back up your statement? If I'm wrong I'd certainly like to know what the flaw in my reasoning is...

Bucko's statement is true, and I'll try to clarify. What he said is that fresh fuel isn't very radioactive, meaning that it can be fabricated, handled, and transported safely with very little exposure to those involved. (The rule of thumb is that you're good to go as long as you are at least two feet away from it. The greater concern with fresh uranium is ingestion, and not even because of dose. It's because it's a heavy metal with many of the same biological hazards as lead.) This is because uranium doesn't decay quickly of its own accord. You don't get any significant power out of it unless you put it into the reactor and start the chain reaction.

Criticality (the onset of the self-sustaining chain reaction) is achieved by bombarding the fresh fuel with neutrons. A few neutrons cause fission of some of the U235 which produces more neutrons which creates even more fission...you probably have a sense of what's going on at that time. Now you have a controlled reaction that is immensely more powerful than a few atoms spontaneously decaying every so often. That's what makes the steam that turns the turbines that run your CFLs and charge your shiny new PHEV. :)

After an atom splits it produces fission products: new atoms that are far less stable than the uranium was. This stuff decays very quickly all by itself, which produces a great deal of radioactivity and heat. So you absolutely can not handle spent fuel in the same manner as fresh fuel. It has to be shielded, by water at first and eventually in a shielded dry cask. It "cools" substantially within the first 48 hours of reactor shutdown but an assembly can still pump out thousands of watts of heat. This is what Bucko is talking about.

Incidentally, this is the primary concern when you talk about a "meltdown." You don't have to worry about a modern reactor running "out of control" so much as cooling the fuel after you have shut it down. Those first 48 hours are critical because you need a working cooling system to keep the fuel from getting too hot just from the decay heat (which is the term given to the heat generated by natural decay of fission products.) If it gets too hot you can melt the metal cladding, which releases everything into the primary coolant. This doesn't automatically mean a massive release of radiation, as there are other barriers between the fuel and the environmnent. But it does pretty much render your reactor useless.

And this is where Pebble Bed ("PBMR") reactors come in. It's a totally different design that uses billiard ball-sized ceramic-clad fuel. The concept is that its fuel is so robust that you can't melt it no matter what happens. Look for that technology to take hold in the coming decades, I think.

Sorry, I ramble.

Thanks for the clarification, Tim!

I still think we should be using that "spent" fuel for less demanding purposes rather than burying it. We're transporting it right now, so why not to another useful location?

Do you think as fuel prices go up, the largest cargo ships might start being equiped with reactors?

Not likely. There is a significant cost and weight penalty for mobile nuclear vs. conventional power.

The reason large combatants have nuclear is
1) space is more important than weight
2) operation costs for another oiler in a BG would be significant
3) Tactically, not being constrained by fuel range is a huge advantage
4) Speed
5) Subs are infinitely more useful if they're not tied to the surface.

Commercial ships don't do underway refueling, high transit or dash speeds, weight is controlling factor, and they're not being shot a

Also, note that reasons 1 & 2 are invalid if you do a 1:1 swap of boilers for reactors. (Nimitz class carriers carry 2 reactors, Kitty Hawks carried 8 boilers, Enterprise carries 8 reactors and can't use them all)

Thanks for the clarification, Tim!

I still think we should be using that "spent" fuel for less demanding purposes rather than burying it. We're transporting it right now, so why not to another useful location?

Primarily because construction costs for containment would be prohibitively high.

Also, reinserting "Hot" or spent fuel is difficult, if not impossible.

If they could only perfect non-depleting reactors (sodium, pbmr, etc...).

I don't believe that much of the spent fuel from commercial power plants (in the USA) is being sent anywhere, most plants are storing it on site in their spent fuel pools or in dry storage as a temporary measure until a more permanent solution/storage location is completed (yukka mountain).

Thanks for adding the explanation Brick

How many plants are active in the US and how much power do they generate?

How many plants are active in the US and how much power do they generate?

104 reactors, 781 billion kWh. 20% of the USA's electricity. This does not include Naval or Research only reactors.

http://www.ne.doe.gov/pdfFiles/nePrimerWeb1.pdf